1 Discovery of Pentaquarks
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Search for Pentaquarks
Search for Pentaquarks Volker D. Burkert Jefferson Lab Science and Technology Review, Jefferson Lab, June 14, 2004 Office of Thomas Jefferson National Accelerator Facility Science OUTLINE Hadron Spectroscopy and Pentaquarks Evidence for and against Θ+(1540) and other Pentaquarks Theory response to the Θ+(1540) The experimental program at JLab Summary Office of Thomas Jefferson National Accelerator Facility Science Hadron Spectroscopy 101 − Meson: quark-antiquark pair K s u −1/3 p −2/3 u Baryon: three quarks (valence) +2/3 d −1/3 u Pentaquark: 4 quarks + 1 antiquark +2/3 Each quark has a unique • charge (+2/3 or -1/3) d Θ+ • flavor (u,d,s,c,b,t) −1/3 • color (red, green, blue) u s Hadrons must be colorless +2/3 +1/3 d −1/3 + u The Θ represents a new form of quark +2/3 matter containing a minimum of five quarks. Office of Thomas Jefferson National Accelerator Facility Science Types of Pentaquarks •“Non-exotic” pentaquarks – The antiquark has the same flavor as one of the other quarks – Difficult to distinguish from 3-quark baryons Example: uudss, same quantum numbers as uud Strangeness = 0 + 0 + 0 - 1 + 1 = 0 •“Exotic” pentaquarks – The antiquark has a flavor different from the other 4 quarks – They have quantum numbers different from any 3-quark baryon – Unique identification using experimental conservation laws Example: uudds Strangeness = 0 + 0 + 0 + 0 + 1 = +1 Office of Thomas Jefferson National Accelerator Facility Science Hadron Multiplets K Mesons qq π K ∆- ∆++ Baryons qqq N Σ Ξ Ω─ B+S + Baryons built from qqqqq 2 Θ 1 I3 +1/2 1 -1 -1/2 Ξ-- Ξ+ Office of Thomas Jefferson National Accelerator Facility Science The Anti-decuplet in the χSM D. -
Qt7r7253zd.Pdf
Lawrence Berkeley National Laboratory Recent Work Title RELATIVISTIC QUARK MODEL BASED ON THE VENEZIANO REPRESENTATION. II. GENERAL TRAJECTORIES Permalink https://escholarship.org/uc/item/7r7253zd Author Mandelstam, Stanley. Publication Date 1969-09-02 eScholarship.org Powered by the California Digital Library University of California Submitted to Physical Review UCRL- 19327 Preprint 7. z RELATIVISTIC QUARK MODEL BASED ON THE VENEZIANO REPRESENTATION. II. GENERAL TRAJECTORIES RECEIVED LAWRENCE RADIATION LABORATORY Stanley Mandeistam SEP25 1969 September 2, 1969 LIBRARY AND DOCUMENTS SECTiON AEC Contract No. W7405-eng-48 TWO-WEEK LOAN COPY 4 This is a Library Circulating Copy whIch may be borrowed for two weeks. for a personal retention copy, call Tech. Info. Dlvislon, Ext. 5545 I C.) LAWRENCE RADIATION LABORATOR SLJ-LJ UNIVERSITY of CALIFORNIA BERKELET DISCLAIMER This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor the Regents of the University of California, nor any of their employees, makes any warranty, express or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or the Regents of the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof or the Regents of the University of California. -
Baryon (Pentaquark)
PentaquarksPentaquarks inin ChiralChiral SolitonSoliton ModelsModels Bo-Qiang Ma ? Department of Physics, Peking University Feb.17-19, 2004, talk on Feb.18 at Yukawa Institute for Theoretical Physics, Kyoto Univ. In Collaboration with B. Wu Hep-ph/0312041, PRD Hep-ph/0312326, PLB Hep-ph/0311331 1 Search for Exotic Baryon States • Standard Quark Model – classifies hadrons as • mesons ( qq ) • baryons ( qqq ) – also allows “non-standard” or exotic hadron states • multiquark mesons ( qqqq ) • multiquark baryons ( qqqqq ) -> appear as baryon resonances • hybrid states ( qqg or q qqg ) • dibaryons ( qqqqqq ) • glueballs -> no convincing previous evidence for exotic baryon states. 2 Baryon States •All baryons observed before – classified as singlets, octets and decuplets of SU(3) flavor group -> constructed of 3 quarks only, - may have higher orbital angular momentum, resonances – have strangeness from S=-3 to S=0 Y baryon octet with JP=½+ 0 I Z baryon decuplet with JP=(3/2)+ • Exotic Baryons with S=+1 – cannot be formed from only 3 quarks – belong to higher SU(3) multiplet 3 Previous Searches for Exotic Baryons • Ideally: kaon-nucleon (KN) scattering R. Cool et al., PRL 17, 102 (1966) • started in 1966 at BNL BNL 1966 -> “clear” resonance peak found in K+p at M=1.91 GeV and Γ=180 MeV • searches: partial wave analyses in KN scattering – candidates: isoscalar Z0(1780) and Z0(1865) -> give poor evidence (PDG) • dropped from PDG listings after 1986 • reasons for failure: – KN (in)elastic scattering at p(K) corresponding to 1.74 ≤ MZ ≤ 2.16 GeV – resonance widths large: 70 ≤ ΓZ ≤ 845 MeV – MIT bag model predictions: MZ ≥ 1.7 GeV • Λ(1405): molecular meson-baryon state uudsu ? – interpretation problematic: could be uds -> ambiguity remains 4 PentaquarkPentaquark StatesStates • Predictions of pentaquark states with both strange and charm (by Lipkin et al.), no evidence found in experimental searches for more than ten years. -
The End of the Constituent Quark Model?
The End of the Constituent Quark Model? F.E. Close Department of Theoretical Physics, University of Oxford, 1 Keble Rd., Oxford, OX1 3NP, United Kingdom; [email protected] Abstract. In this conference summary talk at Hadron03, questions and challenges for Hadron physics of light flavours are outlined. Precision data and recent discoveries are at last exposing the limitations of the naive constituent quark model and also giving hints as to its extension into a more mature description of hadrons. These notes also pay special attention to the positive strangeness baryon Θ+(1540) and include a pedagogic discussion of wavefunctions in the pentaquark picture, their relation with the Skyrme model and related issues of phenomenology. Introduction My brief was to concentrate on light hadrons; but where do heavy hadrons end and light begin? I shall focus on what heavy flavours can teach us about light, and vice versa. The possible discovery of an exotic and metastable baryon with positive strangeness, the Θ+(1540), has led to an explosion of interest in recent months and throughout this conference. There was a dedicated discussion session about it, which highlighted much confusion. In the hope of clarifying some of the issues, I have decided to devote a considerable part of this summary to a pedagogic description of wavefunctions and a review of some of the emerging literature that drew comment at the conference. Light Hadron Spectroscopy and Dynamics: Present and Future arXiv:hep-ph/0311087v1 6 Nov 2003 As regards the future of light hadrons experimentally: we have heard of several examples of innovative methods involving high energy machines. -
Unification of Standard and Exotic Matter Through a $ Z 2 $ Symmetry
Unification of standard and exotic matter through a Z2 symmetry Ernesto A. Matute∗ Departamento de F´ısica, Universidad de Santiago de Chile, Casilla 307, Santiago 2, Chile We consider a scenario in which the discrete weak symmetry between quarks and leptons is extended to the weak force by introducing exotic partners. We conjecture that there exists a hidden discrete symmetry P,˜ defining a Z2 group, between standard and exotic quarks and leptons. The × × × × × ˜ unified model SU(3)q SU(3)q˜ SU(2)qℓ˜ SU(2)qℓ˜ U(1)Y P is discussed, where the unifying discrete symmetry extends over particles and forces. It is shown that the lighter neutral and charged weak bosons generated upon spontaneous symmetry breaking have the same properties as those of the standard model. Cabbibo-Kobayashi-Maskawa unitarity is used to set a mass of order 2.8 TeV for the nonstandard weak bosons, which do not exhibit quark-lepton universality. A grand unified × × ˜ theory of (GUT)qℓ˜ (GUT)qℓ˜ P type, with decay of exotic matter into standard matter and no decay of the ordinary nucleon, is put forward. PACS numbers: 12.60.Cn; 11.30.Hv; 12.10.Dm; 14.70.Pw The unification of quark and lepton properties under unified form G ˜ Gqℓ P,˜ whereq ˜ and ℓ˜ denote exotic qℓ × ˜ × strong and electroweak interactions through a continu- quarks and exotic leptons, respectively, and P,˜ hereafter ous or discrete symmetry has been one of the targets referred to as exotic symmetry, denotes the discrete sym- of research efforts over the last few decades [1]. -
Quark Masses, Hyperfine Interactions, and Exotic Baryons
Quark masses, hyperfine interaction and exotic baryonsa Marek Karliner ([email protected]) Cavendish Laboratory, Cambridge University, United Kingdom and School of Physics and Astronomy,Tel Aviv University, Israel In collaboration with Harry J. Lipkin ahep-ph/0307243 and hep-ph/0307343 Marek Karliner – Pentaquark Workshop, Jlab, Nov. 7, 2003 1 Renaissance of QCD Spectroscopy Several new surprising experimental results: Marek Karliner – Pentaquark Workshop, Jlab, Nov. 7, 2003 2 Renaissance of QCD Spectroscopy Several new surprising experimental results: • two new extremely narrow mesons containing c and s¯ quarks (BaBar, CLEO, BELLE) Marek Karliner – Pentaquark Workshop, Jlab, Nov. 7, 2003 3 Renaissance of QCD Spectroscopy Several new surprising experimental results: • two new extremely narrow mesons containing c and s¯ quarks (BaBar, CLEO, BELLE) • new very narrow resonance precisely at D0∗D0 threshold (Belle, CDF) Marek Karliner – Pentaquark Workshop, Jlab, Nov. 7, 2003 4 Renaissance of QCD Spectroscopy Several new surprising experimental results: • two new extremely narrow mesons containing c and s¯ quarks (BaBar, CLEO, BELLE) • new very narrow resonance precisely at D0∗D0 threshold (Belle, CDF) • enhancements near pp¯ thresholds (BES, BELLE) Marek Karliner – Pentaquark Workshop, Jlab, Nov. 7, 2003 5 Renaissance of QCD Spectroscopy Several new surprising experimental results: • two new extremely narrow mesons containing c and s¯ quarks (BaBar, CLEO, BELLE) • new very narrow resonance precisely at D0∗D0 threshold (Belle, CDF) • enhancements near pp¯ thresholds (BES, BELLE) • exotic 5-quark KN resonances: Θ+, Ξ∗−− Marek Karliner – Pentaquark Workshop, Jlab, Nov. 7, 2003 6 Renaissance of QCD Spectroscopy Several new surprising experimental results: • two new extremely narrow mesons containing c and s¯ quarks (BaBar, CLEO, BELLE) • new very narrow resonance precisely at D0∗D0 threshold (Belle, CDF) • enhancements near pp¯ thresholds (BES, BELLE) • exotic 5-quark KN resonances: Θ+, Ξ∗−− Marek Karliner – Pentaquark Workshop, Jlab, Nov. -
Exotics with Heavy Quarks
Proceedings of the 8th International Conference on Quarks and Nuclear Physics (QNP2018) Downloaded from journals.jps.jp by Deutsches Elek Synchrotron on 11/15/19 Proc. 8th Int. Conf. Quarks and Nuclear Physics (QNP2018) JPS Conf. Proc. 26, 011005 (2019) https://doi.org/10.7566/JPSCP.26.011005 Exotics with Heavy Quarks Marek Karliner School of Physics and Astronomy, Tel Aviv University, Israel E-mail: [email protected] (Received May 27, 2019) I discuss recent developments regarding new types of hadrons involving heavy quarks: hadronic molecules, doubly heavy baryons, stable tetraquarks and others. I also explain how the discovery of the doubly heavy baryon leads to a quark-level analogue of nuclear fusion, with energy release per reaction an order of magnitude greater than in ordinary fusion. KEYWORDS: QCD,exotic hadrons,heavy quarks,hadronic molecules,tetraquarks,pentaquarks 1. Social Life of Heavy Quarks Studying heavy exotic hadrons is somewhat similar to investigating the social life of heavy quarks. The relevant questions one would be asking in this context are (a) Who with whom? (b) For how long? (c) A short episode? or (d) “Till Death Us Do Part”? In the following I will try to an- swer some of the obvious concrete questions about exotic hadrons: Do they exist? If they do, which ones? What is their internal structure? How best to look for them? Quarks are fundamental building blocks of protons, neutrons and all hadrons. Paraphrasing Orwell [1], one can say that all quarks are equal, but heavy quarks are more equal than others. In recent years a lot of attention has been devoted to new combinations of hadrons containing heavy quarks, including exotics [2,3]: • hadronic molecules, Zb, Zc tetraquark-like states, and more recently the LHCb pentaquark • prediction and discovery of doubly-charmed baryon • a stable bbu¯d¯ tetraquark Hadrons with heavy quarks are much simpler than quarks containing only light quarks. -
Pentaquarks from Chiral Solitons
Pentaquarks from chiral solitons Maxim V. Polyakov Liege Universitiy & Petersburg NPI Outline: -Predictions -Post-dictions -Implications GRENOBLE, March 24 Baryon states All baryonic states listed in PDG can be made of 3 quarks only * classified as octets, decuplets and singlets of flavour SU(3) * Strangeness range from S=0 to S=-3 A baryonic state with S=+1 is explicitely EXOTIC •Cannotbemadeof 3 quarks •Minimal quark content should be qqqqs , hence pentaquark •Must belong to higher SU(3) multiplets, e.g anti-decuplet observation of a S=+1 baryon implies a new large multiplet of important baryons (pentaquark is always ocompanied by its large family!) Searches for such states started in 1966, with negative results till autumn 2002 Possible reason: searches were for heavy and wide states Theoretical predictions for pentaquarks 1. Bag models [R.L. Jaffe ‘76, J. De Swart ‘80] Jp =1/2- lightest pentaquark Masses higher than 1700 MeV, width ~ hundreds MeV Mass of the pentaquark is roughly 5 M +(strangeness) ~ 1800 MeV An additional q –anti-q pair is added as constituent 2. Soliton models [Diakonov, Petrov ‘84, Chemtob‘85, Praszalowicz ‘87, Walliser ‘92] Exotic anti-decuplet of baryons with lightest S=+1 Jp =1/2+ pentaquark with mass in the range 1500-1800 MeV. Mass of the pentaquark is rougly 3 M +(1/baryon size)+(strangeness) ~ 1500MeV An additional q –anti-q pair is added in the form of excitation of nearly massless chiral field The question what is the width of the exotic pentaquark In soliton picture has not been address untill 1997 It came out that it should be „anomalously“ narrow! Light and narrow pentaquark is expected −> drive for experiments [D. -
Tetraquark and Pentaquark Systems in Lattice QCD
Journal of Modern Physics, 2016, 7, 774-789 Published Online April 2016 in SciRes. http://www.scirp.org/journal/jmp http://dx.doi.org/10.4236/jmp.2016.78072 Tetraquark and Pentaquark Systems in Lattice QCD Fumiko Okiharu1, Takumi Doi2, Hiroko Ichie3, Hideaki Iida4, Noriyoshi Ishii5, Makoto Oka3, Hideo Suganuma6, Toru T. Takahashi7 1Faculty of Education, Niigata University, Niigata, Japan 2Theoretical Research Division, Nishina Center, RIKEN, Wako, Japan 3Department of Physics, Tokyo Institute of Technology, Tokyo, Japan 4Research and Education Center for Natural Sciences, Keio University, Kanagawa, Japan 5Research Center for Nuclear Physics (RCNP), Osaka University, Ibaraki, Japan 6Department of Physics, Graduate School of Science, Kyoto University, Kyoto, Japan 7Gunma National College of Technology, Maebashi, Japan Received 12 February 2016; accepted 26 April 2016; published 29 April 2016 Copyright © 2016 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract We study multi-quark systems in lattice QCD. First, we revisit and summarize our accurate mass measurements of low-lying 5Q states with J = 1/2 and I = 0 in both positive- and negative-parity channels in anisotropic lattice QCD. The lowest positive-parity 5Q state is found to have a large mass of about 2.24 GeV after the chiral extrapolation. To single out the compact 5Q state from NK scattering states, we use the hybrid boundary condition (HBC), and find no evidence of the com- pact 5Q state below 1.75 GeV in the negative-parity channel. Second, we study the multi-quark po- tential in lattice QCD to clarify the inter-quark interaction in multi-quark systems. -
Baryogenesis from B Meson Oscillations
PHYSICAL REVIEW D 100, 075002 (2019) Baryogenesis from B meson oscillations † Ann E. Nelson * and Huangyu Xiao Department of Physics, University of Washington, Seattle, Washington 98195-1560, USA (Received 17 June 2019; published 1 October 2019) We show how CP violating B meson oscillations in conjunction with baryon number violating decays can generate the cosmological asymmetry between matter and antimatter, and explore the parameter space of a simple, self-contained model, which can be tested via exotic B meson decays, and via the charge asymmetry in semileptonic decays of neutral B mesons. DOI: 10.1103/PhysRevD.100.075002 I. INTRODUCTION visible matter-anti-matter asymmetry and asymmetric dark matter [6] via B-meson decays. In the present Baryogenesis—generating the cosmological asymme- work, we reexamine the simpler model of Ref. [4],and try between matter and antimatter—requires physics show that for a different parameter range that was not beyond the Standard Model (SM). The pioneering work considered in the previous work, baryon number vio- of Sakharov [1] found three necessary conditions: baryon B0 number violation, C and CP violation, and departure lating decays of mesons are allowed by experiment, from thermal equilibrium. Baryon number violation potentially observable, and could be the explanation for occurs nonperturbatively in the Standard Model [2]. baryogenesis. The baryogenesis scenario described here begins in the CP violation also occurs, however the standard model prenucleosynthesis early universe with the decays of CP violation appears to be too small to explain the a long lived scalar into b-quarks and antiquarks. These observed baryon asymmetry. Finally, the minimal decays are assumed to take place late enough and at Standard Model contains no mechanism for departure low enough temperature to allow hadronization, but from thermal equilibrium. -
GLUEBALLS, HYBRIDS, PENTAQUARKS: Introduction to Hadron Spectroscopy and Review of Selected Topics
GLUEBALLS, HYBRIDS, PENTAQUARKS: Introduction to Hadron Spectroscopy and Review of Selected Topics Eberhard Klempt Helmholtz–Institut f¨urStrahlen- und Kernphysik der Universit¨atBonn Nußallee 14 -16, 53115 Bonn, Germany E-mail: [email protected] Hadron spectroscopy has received revitalised interest due to the discovery of states with unexpected properties. The BABAR collaboration found a DsJ(2317) (likely scalar) me- son, accompanied by a second state, the DsJ(2463) with preferred spin J = 1, discovered at CLEO. Both are found at an unexpectedly low mass and are narrow. A further nar- row resonance, discovered at BELLE in its decay into ¼¼J/Ã, might be a DD¤ molecule or a cc¯ meson in which the color field, concentrated in a flux tube, is excited. A qq¯ state with excited gluon field is called hybrid, such excitations are expected from QCD. The mass of the state at the DD¤ threshold underlines the importance of meson–meson interactions or four–quark dynamics at the opening of new thresholds. BES reports a signal in radiative J/Ã decays into a proton and an antiproton which has the proper- ties as predicted for NN¯ quasi-nuclear bound states. And last not least the Θ+(1540), seen in several experiments, shows that the ’naive’ quark model needs to be extended. There is also considerable progress in understanding the dynamics of quarks in more conventional situations even though the view presented here is not uncontested. In me- son and in baryon spectroscopy, evidence is emerging that one–gluon–exchange does not provide the appropiate means to understand low–energy QCD; instanton–induced inter- actions yield much more insight. -
Neutrino Free Download
NEUTRINO FREE DOWNLOAD Frank Close | 192 pages | 01 Apr 2012 | Oxford University Press | 9780199695997 | English | Oxford, United Kingdom What is a neutrino? Astroparticle Physics. Enhancing the basic framework to accommodate their mass is straightforward by adding a right-handed Lagrangian. Oneworld Publications. The coincidence of both events — positron annihilation and neutron capture — gives a unique signature of an antineutrino interaction. How do stars collapse and form supernovae? Bibcode : JPhCS. In Stanislav Mikheyev and Alexei Smirnov expanding on work by Neutrino Wolfenstein noted that flavour oscillations can be modified when neutrinos propagate through matter. Quantum gravity. The first pendulum is set in motion by the experimenter while the second begins at rest. When a neutrino hits the heavy water in the detector's spherical vessel, a cone of light--here clearly visible in red--spreads out to sensors Neutrino the device. Though widely reported in the media, the results were greeted with a great deal of skepticism from the scientific community. The smallest modification to the Standard Model, which only has Neutrino neutrinos, is to allow these left-handed neutrinos to Neutrino Majorana masses. Physical Review C. Categories : Astrophysics Elementary particles. Neutrino November Neutrino Main article: Seesaw mechanism. In all observations so far of leptonic processes despite extensive and continuing searches for exceptionsthere is Neutrino any change in overall lepton number; for example, if total lepton number is zero in the initial state, electron neutrinos appear in the final state together with only positrons anti-electrons or electron-antineutrinos, and electron antineutrinos with electrons or electron neutrinos. This marks the first use of neutrinos for communication, and Neutrino research may permit binary neutrino messages to be sent immense distances through even the densest Neutrino, such as the Earth's core.